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From | Aaron Kirkman <ak5791@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | st: Generate a random double between -1 and 1 |
Date | Sun, 2 Sep 2012 14:26:12 -0500 |
I have a situation where I need to generate random real numbers between -1 and 1, and I'm wondering if there is a better way to accomplish this. Right now, I use this: clear set obs 100000000 gen double eps = -1 + 2 * runiform() summ eps While this is probably acceptable, as the theoretical mean is 0, it's problematic because multiplying 2 * runiform() excludes half the possible values between -1 and 1. Is there a built-in way to do this in a way that won't exclude values, or is this method sufficient? In practice, I may generate as few as 30 random numbers and as many as 100,000,000 (if that's relevant). Thank you, Aaron Kirkman * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/